The social life of corvids
Nicola S. Clayton1, and Nathan J. Emery2,1Department of Experimental Psychology, University of Cambridge, Cambridge CB2 3EB, UK
2Sub-department of Animal Behaviour, University of Cambridge, Cambridge CB3 8AA, UK

Available online 20 August 2007.

Article Outline

Of the 120 species of birds in the corvid family, which includes the crows, ravens, magpies and jays, the bare-faced rook is perhaps the most social of them all. At a rookery in Norfolk, for example, winter roosts can number up to 60,000 individuals. The name for a congregation of rooks is a ‘parliament’. In English folklore, parliament is an apt name for rook justice, as it is said that rooks form a circle around a wrongdoer producing a cacophony of calls and caws which can go on for hours until the offender is either attacked and killed or released to live another day. Although only fiction, such tales reflect their canny reputation as thieves and tricksters, as well as possessors of great wisdom.
Like most birds, corvids are monogamous, and the core unit is therefore the mated pair. This pair bond is typically for life, and the pair remains together throughout the year. For example, rooks and ravens find a partner during the autumn months, taking part in impressive aerobatic displays and food sharing which may be to assess the quality of a potential mate. Once juvenile rooks and ravens pair, they engage in extensive mutual preening and bill twining (bill holding) and support one another in fights.

I regularly peruse crow photographs on flickr. Today I found this one. What an excellent photograph, don't you think? Under the photograph the question was asked, "Are crows monogamous?" Are crows monogamous? Are ravens monogamous? I thought this would be a good post for today.
Yes, crows and ravens are monogamous. They generally mate for life. They are social birds. John M. Marzluff and Tony Angell stated the following about crows in their book In the Company of Crows and Ravens,
"Crows and ravens care for each other, spend years living at home, engage in foreplay, and mate for life but now and then mate with others. Large groups cooperate to sleep in safety, drive away mutual enemies, and maybe even dole out justice."
Interesting, eh? We could learn a thing or two from crows and ravens. Maybe being close with family and friends is not just for the birds...
Thanks to mikE~510 for the photograph, the question and the inspiration to write this post!